SYDNEY key forward Logan McDonald has highlighted how the Swans' flexible attack sparked a 19-point comeback victory over St Kilda, praising Isaac Heeney's game-changing impact following a crucial tactical shift.

Early in the match, the Saints outworked the Swans in both contested possession and territory. Driven by intense pressure, clearance control and midfielder Hugh Boxshall’s tight tag on Heeney, St Kilda stifled Sydney's midfield flow, leaving the visitors heavily reliant on back-half transition play.

"The Saints were on top in that midfield battle early, but after (quarter-time) we really controlled the game. Brody (Grundy) was enormous in there, and so was Isaac, Chad (Warner) and Errol (Gulden) getting the ball forward," McDonald said on Tuesday.

"Once we were able to play that front-half territory game, we’re a pretty hard team to beat."

To break the tag and counter St Kilda's stoppage dominance, coach Dean Cox shifted Heeney deep forward while assigning Jai Serong to neutralise Saints playmaker Nasiah Wanganeen-Milera.

The move paid off as Heeney turned the tide, finishing with 22 disposals, seven clearances and two crucial goals.

McDonald also stepped up with four majors of his own, including a vital goal early in the fourth quarter to anchor Sydney’s dominant +13 contested possession and +7 clearance advantage in the final term.

Sydney's last-quarter surge was further fuelled during an extended delay following a severe leg injury to defender Will Edwards, with the Swans using the break to regroup before storming home with a seven-goals-to-two final quarter.

To make room inside 50, McDonald explained that he actively adjusted his work rate and leading patterns for Heeney and Warner.

"Isaac is just about the best player in the game but (the best) one-on-one player, so pretty much just get out of his way," McDonald said.

"Get up the ground and open it up for him. If we can kick it to him when we're in trouble, he'll most likely mark it and kick us a goal."

He added that rotation and versatility are central to Sydney's frontline identity.

"It's awesome. I think we're pretty dangerous up there. We spin the wheel up there regularly, whether it's Isaac or Chad coming down and contributing. 'Paps' (Tom Papley) has been awesome since coming back from injury as well."

Cox confirmed post-match that as long as Heeney communicates with the forward line and players interchange smoothly, this positional fluidity will remain a staple, a structure McDonald fully endorses.

"We've got a lot of players who can play a lot of different positions," McDonald noted.

"They can spin the wheel (between) inside (mid) and half-forward. Whether that's in play or at stoppages, it makes us hard to play on and gives opposition something to think about. It makes us dangerous. It brings our best players into the game."

The win was tempered by a major injury blow, with key midfielder James Rowbottom suffering a broken hand requiring surgery that will rule him out for the rest of the home-and-away season.

McDonald explained how the engine room adjusted to compensate for Rowbottom's loss.

"Obviously the Saints are a strong midfield. They've got two of the premier rucks in the competition, and they run hard. Their transition game is strong," he said.

"To see 'Rowie' (Rowbottom) go down, who controls a lot of our pressure and scramble work in there, we had to swing some magnets around. 'Jordy' (James Jordon) shifted from the wing, and we put Jai (Serong) on 'Nas' (Wanganeen-Milera). He did a really good job and was able to nullify him as best he could.

"We also saw the likes of Billy Cootee get a look in (through the midfield-forward rotation), and everyone just stepped up a bit more and played their role. I think we got on top in clearance and were able to get some front-half game off the back of that."

Looking ahead to how the Swans will replace their midfield engine, McDonald admitted long-term plans are still taking shape, though he remains confident in their depth.

"I'm not too sure. It's our first session today, so I'm not too sure what that looks like. I'm sure the coaches will work through that," he said.

"Our VFL side has been pretty strong all year. A lot of boys have been putting their hands up regularly, and it's been tough for spots. Some boys have gone out after playing good footy as well, so we've got full confidence that whoever comes in will play their role well.”

Despite the setback, McDonald expects Rowbottom to stay heavily involved off the field as he prepares to return for the finals series.

"He'll be right, 'Rowie'. He's the ultimate professional and he'll do everything he can to get back. He was already back at the club this morning contributing in meetings and whatnot," McDonald said.

"He'll be ready to go, hopefully, when we need him.

"He's a natural leader of the footy club, and he'll keep helping us end the season as best we can, whether he's on the field or not."